nelson and the mamola's went to the cemetery and walked to the grave of ed's father. >> it's nice when you get a nice ending. >> reporter: the story the sergeant told them was this. mamola was a constable during the years of prohibition. >> go to it boys. >> reporter: joining in the war was an up and coming alameda county district attorney warren who would one day become chief justice of the supreme court. warren also enlisted trustworthy officers including mamola. in revenge for bootleggers ambush constable mamola in richmond beat him and shot him with his own gun. now edward knows who his father was an honest cop who did his job and who died trying to fight off four thugs. >> it was a blessing when he came down here. because i learned the truth about the whole story. >> as the u.s. government waged an all out war on the gangsters who ran the illegal liquor trade, some of them would end up in federal prison and eventually a few of them would be sent to the national's newest and most forbidding prison, alcatraz. bob mackenzie brought us this look back at the island prison and the men w